I've got one in the package I think in the new to me 37 that just got delivered down here to lake Cumberland. I will try and go take a pic for you. Although I can't load pics here as I don't understand the sizing limitations.

Well I was mistaken I have a used impeller it's a jabsco and has a part number of 18948-0001. It is a 12 vane impeller I assume came out of my 440's. I have a spare here labeled gen that is much smaller. Hope this helps.